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I want to use some art from OpenGameArt for my game. The piece I want to use is a sprite sheet containing a bunch of sprite tiles compiled into a single PNG:

enter image description here

I want to create a JSON file with the names and coordinates for each tile. Doing this manually would probably take took long.

I've tried TexturePacker but it seems that it only accepts separate image files which it compiles into a single image. It doesn't have an option to load precompiled sprite sheets; then select and name each tile inside of it.

How could I accomplish this?

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  • \$\begingroup\$ For your example sprite sheet, do you want the medium and large tree (and cloud) to be treated as a single sprite, or do you expect them to be cut up into little tiles? \$\endgroup\$ – Tim Holt Jan 13 '15 at 17:36
  • \$\begingroup\$ in my case it will be easier to work with sprites as single objects. \$\endgroup\$ – Shkarik Jan 13 '15 at 19:09
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There are tools out there that can help you, such as Shoebox. But tools-recommendation questions aren't appropriate here, so instead I'll describe a basic process you could use to do this yourself.

Since the sprites in the sheet are regular (that is, they're all the same size) you can pretty easily write a program that produce a set of rectangle data in JSON based on the size of the image. You only need to give this program the image file name, the desired tile size, and the output file name. It would then:

  • Load the image file, get the width and height.
  • Generate a set of tiled rectangles, starting with (0, 0, tileWidth, tileHeight), by dividing the width and height accordingly.
  • Generate a placeholder name for each tile, such as tile00 through tile24 or whatever.
  • Write all that information to the output JSON file.

You can then open the file up and alter the placeholder names to match what you actually see on the sprite sheet for that section. No matter you're going to be naming the tiles yourself. You could aid yourself in this process by adding the following features to your program:

  • Perform a simple check on the contents of the sprite sheet in every rectangle to see if the rectangle is empty. If so, that space can be considered empty and you can avoid generating the name or bounds information in the output.
  • Write out a separate copy of the image where you've rendered a grid (in some easily visible color, like hot pink) over each tile and annotated each tile with the number used in the placeholder name. This will help you more easily match up the placeholder name with the image and help you produce better names quicker.
  • In the case where you want to consider some sprites to be larger than the otherwise-mostly-regular ones (for example, the two larger trees in your example), you can manually adjust the output file to combine the bounds of the individual tiles into a larger tile, deleting the extra entries.

You can write this tool in any language, although one with built-in support for all the appropriate operations (opening PNGs, annotating them, simple math primitives like rectangles) would be ideal. C#, for example, would make a good choice and you could probably write such a thing very easily if you didn't want to just use an existing tool, if you needed to build thing into a customized asset pipeline, or if you wanted to provide extra options or UI for interaction (for example, your tool could present the sheet with the grid overlayed and allow you to drag-select rectangular regions of the base tile size that constitute "larger" sprites, like the aforementioned trees, saving you the manual fix-up step).

It's impossible to get away from having to do at least some manual work on the data (in the most general case), but simple tools like the above can help you alleviate the majority of the repetitive grunt work inherent to the process.

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    \$\begingroup\$ The example sprite sheet he shows does not use regular (same sized) sprites, so I am not sure how this approach would work in the given example. Specifically I'm talking about the trees. I think by hand is the only way to accomplish this. \$\endgroup\$ – Tim Holt Jan 13 '15 at 17:33
  • \$\begingroup\$ Well, I didn't measure them, but they look regularized to me. The middle-ish tree, for example, looks like it is evenly composed from four tiles. I see what you are saying, though, I'll make a note of that. \$\endgroup\$ – Josh Jan 13 '15 at 17:37
  • \$\begingroup\$ Agreed that yes they are made up of regular sized tiles, but whether the author wishes to display the tree out of multiple smaller tiles or as a single one I suppose is my point/question. \$\endgroup\$ – Tim Holt Jan 13 '15 at 18:50
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In case anyone is looking for alternative answer/solution:

You can actually use paint.net to generate spritesheets from individual images or vise versa with all the file(s) automatically named incrementally, although you have to install a plugin. Don't worry it's all free, and you can also benefit from other great plugins to help manage your work.

http://www.getpaint.net/index.html - get Paint.net here http://forums.getpaint.net/index.php?/topic/15260-plugin-index/ - dl the plugins here

[Specific links]

(P.S. Just remove the spaces, it's my first time posting here so I don't have enough privilege to post more than 2 links I think)

(Sprite Matrix) -> http:// forums . getpaint . net/index . php?/topic/31670-png-sprite-sheet-matrix-march-31-2015/

(Spritesheet Animation Test) -> http:// forums . getpaint . net/index .php?/topic/14848-spritesheet-animation-plugin/

(Alternative spritesheet exporter) -> http:// forums . getpaint . net/index.php?/topic/26202-spritesheet-export-plugin/

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